Abstract
In this paper, experimental results regarding the effect of asymmetric temperature distributions on shape changes of different ring types due to heat treatment will be presented. The main part of the distortion can be attributed to a distortion mechanism which is caused by the interaction of an inhomogeneous temperature distribution and the corresponding local phase transformation: In particular plastic strains by transformation plasticity dominate the change in roundness and the change of the angle of the raceways. To evaluate the portion on roundness deviation which can be attributed to sole thermal stress and/or transformation plasticity effects, experiments with rings produced from austenitic steel (material SAE 304) were examined. In addition, conical rings were heat treated, since the ring geometry has a large influence on the temperature fields during heat treatment. The experimental results were compared with the theoretical description of distortion potential by strain analysis, to identify the necessary inhomogeneous distribution of different carriers of the distortion potential which lead to the observed change in roundness deviation.